Scheme Comparison Study Of Bridge And Tunnel In Yangtze River Channel Of Shanghai-nantong Railway

With rapid development of national economy and great growth in traffic, theconstruction speed of high-speed railway, as well as highway and urban light rail has beengreatly increased in China in recent years. Shanghai-Nantong railway, connecting NantongCity to the north and Shanghai City to the south, is one of the most important parts ofnational rail network of the coastal passage and Yangtze River Delta Intercity Rail. Severalecomical powerful cities, such as Shanghai City, Nantong City and Suzhou City, are all inthis route. Yangtze River crossing channel, located in Xuliujing Reaches, about0.3-8kmdownstream of Su-Tong Yangtze River Highway Bridge, is the controlling project of thisrailway.In order to save resources of River crossing channel and construction investment,"three in one" channel combined the railway, highways and light rail will be used inShanghai-Nantong railway Yangtze River channel. Both bridge and tunnel projects hadbeen successfully applied in tunnel engineerings across river or sea in domestic andinternational engineering practices. However, the bridge schemes are always recommendedin multi-channel construction.In this paper, the schemes comparison of bridge and tunnel in Yangtze River Channelin Shanghai-Nantong Railway is selected as the engineering background, main work andconclusions are summarized as follows:1. The basic conditional informations of Yangtze River Channel in Shanghai-NantongRailway were collected and analyzed, and the main technical engineering standards werealso introduced for following study in this paper.2. Study on the comparison of bridge schemes and tunnel schemes combined railway/highway for Shanghai-Nantong railway Yangtze River channel engineering was carried outseparately. Bridge and tunnel scheme are compared and anlyzed considering the reliabilityof technology, engineering external conditions, operating maintenance conditions andeconomic rationality, and the study also focused on bridge site selection, bridge typeselection. 3. Relevant suggestions and measures were proposed for the selection of bridge andtunnel schemes. Tunnel scheme has high technological difficulties and high cost comparedto the bridge scheme. The combined highway and railway bridge scheme located at3km or8km downstream of Su-Tong Yangtze River Bridge is recommended.The highway and railway combined Yangtze River bridge in Shanghai-Nantongrailway construction conditions have four features: great river breadth, deep buried rock,complex river condition, high standard navigation, so the bridge construction scale andtechnical difficulty are very great whether the double pylon cable-stayed bridge with1092m main span at3km downstream bridge site or five pylon cable-stayed bridge with4x588m main span at8km downstream bridge site. There are a number of key technical issuesneed to be studied in the next phase as soon as possible, so it will provide the necessarytechnical reserves.